Updated kernel-rt packages that fix multiple security issues and severalbugs are now available for Red Hat Enterprise MRG 1.2.

The Red Hat Security Response Team has rated this update as havingimportant security impact. Common Vulnerability Scoring System (CVSS) basescores, which give detailed severity ratings, are available for eachvulnerability from the CVE links in the References section.

2. Relevant releases/architectures:

MRG Realtime for RHEL 5 Server - i386, noarch, x86_64

3. Description:

The kernel-rt packages contain the Linux kernel, the core of any Linuxoperating system.

This update fixes the following security issues:

* a deficiency was found in the fasync_helper() implementation. This couldallow a local, unprivileged user to leverage a use-after-free of locked,asynchronous file descriptors to cause a denial of service or privilegeescalation. (CVE-2009-4141, Important)

* multiple flaws were found in the mmap and mremap implementations. Alocal, unprivileged user could use these flaws to cause a local denial ofservice or escalate their privileges. (CVE-2010-0291, Important)

* a missing boundary check was found in the do_move_pages() function in thememory migration functionality. A local user could use this flaw to cause alocal denial of service or an information leak. (CVE-2010-0415, Important)

* a NULL pointer dereference flaw was found in the ip6_dst_lookup_tail()function. An attacker on the local network could trigger this flaw bysending IPv6 traffic to a target system, leading to a system crash (kernelOOPS) if dst-gt;neighbour is NULL on the target system when receiving an IPv6packet. (CVE-2010-0437, Important)

* a NULL pointer dereference flaw was found in the Fast Userspace Mutexes(futexes) implementation. The unlock code path did not check if the futexvalue associated with pi_state-gt;owner had been modified. A local user coulduse this flaw to modify the futex value, possibly leading to a denial ofservice or privilege escalation when the pi_state-gt;owner pointer isdereferenced. (CVE-2010-0622, Important)

* an information leak was found in the print_fatal_signal() implementation.When "/proc/sys/kernel/print-fatal-signals" is set to 1 (the default valueis 0), memory that is reachable by the kernel could be leaked touser-space. This issue could also result in a system crash. Note that thisflaw only affected the i386 architecture. (CVE-2010-0003, Moderate)

* a flaw was found in the kernel connector implementation. A local,unprivileged user could trigger this flaw by sending an arbitrary amount ofnotification requests using specially-crafted netlink messages, resultingin a denial of service. (CVE-2010-0410, Moderate)

* missing capability checks were found in the ebtables implementation, usedfor creating an Ethernet bridge firewall. This could allow a local,unprivileged user to bypass intended capability restrictions and modifyebtables rules. (CVE-2010-0007, Low)

This update also fixes the following bugs:

* references were missing for two LSI MegaRAID SAS controllers alreadysupported by the kernel, preventing systems using these controllers frombooting. (BZ#554664)

* a typo in the fix for CVE-2009-2691 resulted in gdb being unable to readcore files created by gcore. (BZ#554965)

* values for certain pointers used by the kernel, which should beundereferencable, could potentially be abused when a kernel OOPS occurs.Values that are harder to dereference are now used. (BZ#555227)

* this update redesigns the locking scheme of the TTY process group(tty-gt;pgrp) structure, due to race conditions introduced when tty-gt;pgrpstarted using struct pid instead of pid_t. (BZ#559101)

* the way the NFS kernel server used iget() and the way in which it keptits cache of inode information, could have led to (mainly on busy fileservers) inconsistencies between the local file system and the file systembeing served to clients. (BZ#561275)

Users should upgrade to these updated packages, which contain backportedpatches to correct these issues. The system must be rebooted for thisupdate to take effect.

4. Solution:

Before applying this update, make sure all previously-released erratarelevant to your system have been applied.

This update is available via the Red Hat Network. Details on how touse the Red Hat Network to apply this update are available athttp://kbase.redhat.com/faq/docs/DOC-11259